kconfig: add board Kconfig and defconfig files

This commit adds:
 - arch/${ARCH}/Kconfig
    provide a menu to select target boards
 - board/${VENDOR}/${BOARD}/Kconfig or board/${BOARD}/Kconfig
    set CONFIG macros to the appropriate values for each board
 - configs/${TARGET_BOARD}_defconfig
    default setting of each board

(This commit was automatically generated by a conversion script
based on boards.cfg)

In Linux Kernel, defconfig files are located under
arch/${ARCH}/configs/ directory.
It works in Linux Kernel since ARCH is always given from the
command line for cross compile.

But in U-Boot, ARCH is not given from the command line.
Which means we cannot know ARCH until the board configuration is done.
That is why all the "*_defconfig" files should be gathered into a
single directory ./configs/.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
new file mode 100644
index 0000000..3325af3
--- /dev/null
+++ b/arch/powerpc/Kconfig
@@ -0,0 +1,58 @@
+menu "PowerPC architecture"
+	depends on PPC
+
+config SYS_ARCH
+	string
+	default "powerpc"
+
+choice
+	prompt "CPU select"
+
+config 74xx_7xx
+	bool "74xx"
+
+config MPC512X
+	bool "MPC512X"
+
+config 5xx
+	bool "MPC5xx"
+
+config MPC5xxx
+	bool "MPC5xxx"
+
+config MPC824X
+	bool "MPC824X"
+
+config MPC8260
+	bool "MPC8260"
+
+config MPC83xx
+	bool "MPC83xx"
+
+config MPC85xx
+	bool "MPC85xx"
+
+config MPC86xx
+	bool "MPC86xx"
+
+config 8xx
+	bool "MPC8xx"
+
+config 4xx
+	bool "PPC4xx"
+
+endchoice
+
+source "arch/powerpc/cpu/74xx_7xx/Kconfig"
+source "arch/powerpc/cpu/mpc512x/Kconfig"
+source "arch/powerpc/cpu/mpc5xx/Kconfig"
+source "arch/powerpc/cpu/mpc5xxx/Kconfig"
+source "arch/powerpc/cpu/mpc824x/Kconfig"
+source "arch/powerpc/cpu/mpc8260/Kconfig"
+source "arch/powerpc/cpu/mpc83xx/Kconfig"
+source "arch/powerpc/cpu/mpc85xx/Kconfig"
+source "arch/powerpc/cpu/mpc86xx/Kconfig"
+source "arch/powerpc/cpu/mpc8xx/Kconfig"
+source "arch/powerpc/cpu/ppc4xx/Kconfig"
+
+endmenu